Transparent and conductive films (TCF) have been used extensively in recent years in applications such as touch panel displays, liquid crystal displays, electroluminescent lighting, organic light-emitting diode devices, and photovoltaic solar cells. Indium tin oxide (ITO) based transparent conductive film has been the transparent conductor-of-choice for most applications due to its high conductivity, transparency, and relatively good stability. However, indium tin oxide based transparent conductive films have limitations due to the high cost of indium, the need for complicated and expensive vacuum deposition equipment and processes, and indium tin oxide's inherent brittleness and tendency to crack, especially when it is deposited on flexible substrates.
Two of the most important parameters for measuring the properties of transparent conductive films are total light transmittance (% T) and film surface electric conductivity. Higher light transmittance allows clear picture quality for display applications, higher efficiency for lighting and solar energy conversion applications. Lower resistivity (R) is most desirable for most transparent conductive films applications in which power consumption can be minimized. Therefore, the higher the T/R ratio of the transparent conductive films is, the better the transparent conductive films are.
U.S. Patent Application Publication 2006/0257638A1 discloses a transparent conductive film comprising carbon nanotubes (CNT) and vinyl chloride resin polymer binder.
U.S. Pat. No. 8,049,333 and U.S. Patent Application Publication 2008/0286447A1 disclose a transparent conductive film in which silver nanowires are deposited onto a substrate to form a bare nanowire network followed by overcoating the silver nanowire network with a polymer matrix material to form a transparent conductive film. Polymers such as polyacrylates and carboxyl alkyl cellulose ether polymers were suggested as useful materials for the matrix.
US Patent Application Publication 2008/0286447A1 discloses the use of aromatic triazoles and other nitrogen containing compounds as corrosion inhibitors for silver nanowire based transparent conductors. Long chain alkylthio compounds have also been disclosed as useful corrosion inhibitors.
U.S. Patent Application Publication 2008/0292979A1 discloses a transparent conductive film comprising silver nanowires, or a mixture of silver nanowires and carbon nanotubes. The transparent conductive network is formed either without polymer binder or in a photoimageable composition. The transparent conductive films were coated on both glass and polyethylene terephthalate (PET) supports.
U.S. Pat. No. 8,052,773 describes a transparent conductive film which is formed from coating of silver nanowires to form a network followed by overcoating with a layer of urethane acrylate polymer.
U.S. Patent Application Publication 2011/0024159A1 discloses use of corrosion inhibitors in an overcoat layer of a transparent conductive film.
PCT Patent Publication WO 2011/115603 discloses anticorrosion agents comprising 1,2-diazine compounds for use in transparent conductive films.
US Patent Application Publication 2010/0307792A1 discloses addition of coordination ligands with silver nanowire aqueous dispersions to form sediments followed by separation of such sediments from the supernatant containing halide ions before applying such silver nanowire dispersions in the coating and formation of TCF.
European Patent EP2251389B1 discloses a silver nanowire based ink formulation in which various aqueous silver complex ions were added into silver nanowire based ink in a ratio of complex ion to silver nanowire of no more than 1:64 (w:w).